The present invention relates to techniques for analyzing an image showing a graphical representation.
Helm, R., Marriott, K., Odersky, M., "Building Visual Language Parsers," in proceedings of CHI, 1991 (New Orleans, La., Apr. 28-May 2, 1991), ACM, New York, 1991, pp. 105-112, describe visual language parsers that take as input a set of hand-written gestures recognized by underlying software. A parser combines the gestures into higher-level pictures that are combined in turn until the whole diagram is represented by a single data structure, as illustrated in FIG. 1. Page 106 describes visual languages in which topological relationships use containment, intersection, and touch to relate elements in a diagram. Visual languages based on topological relationships include Venn diagrams and window layout diagrams. Page 107 describes statecharts, illustrated in FIG. 2, that use topological relationships to capture states and their substates. The diagram in the right column on page 107 can be parsed to produce an append program in Visual Prolog, which uses topological relationships, such as "inside" and "touching." Use of constrained set grammars to extract a diagram's meaning is described at pages 108-110. Constraints enable information about spatial layout and relationships to be naturally encoded in the grammar. A topological constraint, a minimization constraint, existential quantification, defining high-level constraints in terms of more primitive constraints, and a negative constraint are described at pages 109-110.